1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_SCSI_HOST_H
3 #define _SCSI_SCSI_HOST_H
4 
5 #include <linux/device.h>
6 #include <linux/list.h>
7 #include <linux/types.h>
8 #include <linux/workqueue.h>
9 #include <linux/mutex.h>
10 #include <linux/seq_file.h>
11 #include <linux/blk-mq.h>
12 #include <scsi/scsi.h>
13 
14 struct block_device;
15 struct completion;
16 struct module;
17 struct scsi_cmnd;
18 struct scsi_device;
19 struct scsi_target;
20 struct Scsi_Host;
21 struct scsi_transport_template;
22 
23 
24 #define SG_ALL	SG_CHUNK_SIZE
25 
26 #define MODE_UNKNOWN 0x00
27 #define MODE_INITIATOR 0x01
28 #define MODE_TARGET 0x02
29 
30 /**
31  * enum scsi_timeout_action - How to handle a command that timed out.
32  * @SCSI_EH_DONE: The command has already been completed.
33  * @SCSI_EH_RESET_TIMER: Reset the timer and continue waiting for completion.
34  * @SCSI_EH_NOT_HANDLED: The command has not yet finished. Abort the command.
35  */
36 enum scsi_timeout_action {
37 	SCSI_EH_DONE,
38 	SCSI_EH_RESET_TIMER,
39 	SCSI_EH_NOT_HANDLED,
40 };
41 
42 struct scsi_host_template {
43 	/*
44 	 * Put fields referenced in IO submission path together in
45 	 * same cacheline
46 	 */
47 
48 	/*
49 	 * Additional per-command data allocated for the driver.
50 	 */
51 	unsigned int cmd_size;
52 
53 	/*
54 	 * The queuecommand function is used to queue up a scsi
55 	 * command block to the LLDD.  When the driver finished
56 	 * processing the command the done callback is invoked.
57 	 *
58 	 * If queuecommand returns 0, then the driver has accepted the
59 	 * command.  It must also push it to the HBA if the scsi_cmnd
60 	 * flag SCMD_LAST is set, or if the driver does not implement
61 	 * commit_rqs.  The done() function must be called on the command
62 	 * when the driver has finished with it. (you may call done on the
63 	 * command before queuecommand returns, but in this case you
64 	 * *must* return 0 from queuecommand).
65 	 *
66 	 * Queuecommand may also reject the command, in which case it may
67 	 * not touch the command and must not call done() for it.
68 	 *
69 	 * There are two possible rejection returns:
70 	 *
71 	 *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
72 	 *   allow commands to other devices serviced by this host.
73 	 *
74 	 *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
75 	 *   host temporarily.
76 	 *
77          * For compatibility, any other non-zero return is treated the
78          * same as SCSI_MLQUEUE_HOST_BUSY.
79 	 *
80 	 * NOTE: "temporarily" means either until the next command for#
81 	 * this device/host completes, or a period of time determined by
82 	 * I/O pressure in the system if there are no other outstanding
83 	 * commands.
84 	 *
85 	 * STATUS: REQUIRED
86 	 */
87 	int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
88 
89 	/*
90 	 * The commit_rqs function is used to trigger a hardware
91 	 * doorbell after some requests have been queued with
92 	 * queuecommand, when an error is encountered before sending
93 	 * the request with SCMD_LAST set.
94 	 *
95 	 * STATUS: OPTIONAL
96 	 */
97 	void (*commit_rqs)(struct Scsi_Host *, u16);
98 
99 	struct module *module;
100 	const char *name;
101 
102 	/*
103 	 * The info function will return whatever useful information the
104 	 * developer sees fit.  If not provided, then the name field will
105 	 * be used instead.
106 	 *
107 	 * Status: OPTIONAL
108 	 */
109 	const char *(*info)(struct Scsi_Host *);
110 
111 	/*
112 	 * Ioctl interface
113 	 *
114 	 * Status: OPTIONAL
115 	 */
116 	int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
117 		     void __user *arg);
118 
119 
120 #ifdef CONFIG_COMPAT
121 	/*
122 	 * Compat handler. Handle 32bit ABI.
123 	 * When unknown ioctl is passed return -ENOIOCTLCMD.
124 	 *
125 	 * Status: OPTIONAL
126 	 */
127 	int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
128 			    void __user *arg);
129 #endif
130 
131 	int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
132 	int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
133 
134 	/*
135 	 * This is an error handling strategy routine.  You don't need to
136 	 * define one of these if you don't want to - there is a default
137 	 * routine that is present that should work in most cases.  For those
138 	 * driver authors that have the inclination and ability to write their
139 	 * own strategy routine, this is where it is specified.  Note - the
140 	 * strategy routine is *ALWAYS* run in the context of the kernel eh
141 	 * thread.  Thus you are guaranteed to *NOT* be in an interrupt
142 	 * handler when you execute this, and you are also guaranteed to
143 	 * *NOT* have any other commands being queued while you are in the
144 	 * strategy routine. When you return from this function, operations
145 	 * return to normal.
146 	 *
147 	 * See scsi_error.c scsi_unjam_host for additional comments about
148 	 * what this function should and should not be attempting to do.
149 	 *
150 	 * Status: REQUIRED	(at least one of them)
151 	 */
152 	int (* eh_abort_handler)(struct scsi_cmnd *);
153 	int (* eh_device_reset_handler)(struct scsi_cmnd *);
154 	int (* eh_target_reset_handler)(struct scsi_cmnd *);
155 	int (* eh_bus_reset_handler)(struct scsi_cmnd *);
156 	int (* eh_host_reset_handler)(struct scsi_cmnd *);
157 
158 	/*
159 	 * Before the mid layer attempts to scan for a new device where none
160 	 * currently exists, it will call this entry in your driver.  Should
161 	 * your driver need to allocate any structs or perform any other init
162 	 * items in order to send commands to a currently unused target/lun
163 	 * combo, then this is where you can perform those allocations.  This
164 	 * is specifically so that drivers won't have to perform any kind of
165 	 * "is this a new device" checks in their queuecommand routine,
166 	 * thereby making the hot path a bit quicker.
167 	 *
168 	 * Return values: 0 on success, non-0 on failure
169 	 *
170 	 * Deallocation:  If we didn't find any devices at this ID, you will
171 	 * get an immediate call to slave_destroy().  If we find something
172 	 * here then you will get a call to slave_configure(), then the
173 	 * device will be used for however long it is kept around, then when
174 	 * the device is removed from the system (or * possibly at reboot
175 	 * time), you will then get a call to slave_destroy().  This is
176 	 * assuming you implement slave_configure and slave_destroy.
177 	 * However, if you allocate memory and hang it off the device struct,
178 	 * then you must implement the slave_destroy() routine at a minimum
179 	 * in order to avoid leaking memory
180 	 * each time a device is tore down.
181 	 *
182 	 * Status: OPTIONAL
183 	 */
184 	int (* slave_alloc)(struct scsi_device *);
185 
186 	/*
187 	 * Once the device has responded to an INQUIRY and we know the
188 	 * device is online, we call into the low level driver with the
189 	 * struct scsi_device *.  If the low level device driver implements
190 	 * this function, it *must* perform the task of setting the queue
191 	 * depth on the device.  All other tasks are optional and depend
192 	 * on what the driver supports and various implementation details.
193 	 *
194 	 * Things currently recommended to be handled at this time include:
195 	 *
196 	 * 1.  Setting the device queue depth.  Proper setting of this is
197 	 *     described in the comments for scsi_change_queue_depth.
198 	 * 2.  Determining if the device supports the various synchronous
199 	 *     negotiation protocols.  The device struct will already have
200 	 *     responded to INQUIRY and the results of the standard items
201 	 *     will have been shoved into the various device flag bits, eg.
202 	 *     device->sdtr will be true if the device supports SDTR messages.
203 	 * 3.  Allocating command structs that the device will need.
204 	 * 4.  Setting the default timeout on this device (if needed).
205 	 * 5.  Anything else the low level driver might want to do on a device
206 	 *     specific setup basis...
207 	 * 6.  Return 0 on success, non-0 on error.  The device will be marked
208 	 *     as offline on error so that no access will occur.  If you return
209 	 *     non-0, your slave_destroy routine will never get called for this
210 	 *     device, so don't leave any loose memory hanging around, clean
211 	 *     up after yourself before returning non-0
212 	 *
213 	 * Status: OPTIONAL
214 	 */
215 	int (* slave_configure)(struct scsi_device *);
216 
217 	/*
218 	 * Immediately prior to deallocating the device and after all activity
219 	 * has ceased the mid layer calls this point so that the low level
220 	 * driver may completely detach itself from the scsi device and vice
221 	 * versa.  The low level driver is responsible for freeing any memory
222 	 * it allocated in the slave_alloc or slave_configure calls.
223 	 *
224 	 * Status: OPTIONAL
225 	 */
226 	void (* slave_destroy)(struct scsi_device *);
227 
228 	/*
229 	 * Before the mid layer attempts to scan for a new device attached
230 	 * to a target where no target currently exists, it will call this
231 	 * entry in your driver.  Should your driver need to allocate any
232 	 * structs or perform any other init items in order to send commands
233 	 * to a currently unused target, then this is where you can perform
234 	 * those allocations.
235 	 *
236 	 * Return values: 0 on success, non-0 on failure
237 	 *
238 	 * Status: OPTIONAL
239 	 */
240 	int (* target_alloc)(struct scsi_target *);
241 
242 	/*
243 	 * Immediately prior to deallocating the target structure, and
244 	 * after all activity to attached scsi devices has ceased, the
245 	 * midlayer calls this point so that the driver may deallocate
246 	 * and terminate any references to the target.
247 	 *
248 	 * Status: OPTIONAL
249 	 */
250 	void (* target_destroy)(struct scsi_target *);
251 
252 	/*
253 	 * If a host has the ability to discover targets on its own instead
254 	 * of scanning the entire bus, it can fill in this function and
255 	 * call scsi_scan_host().  This function will be called periodically
256 	 * until it returns 1 with the scsi_host and the elapsed time of
257 	 * the scan in jiffies.
258 	 *
259 	 * Status: OPTIONAL
260 	 */
261 	int (* scan_finished)(struct Scsi_Host *, unsigned long);
262 
263 	/*
264 	 * If the host wants to be called before the scan starts, but
265 	 * after the midlayer has set up ready for the scan, it can fill
266 	 * in this function.
267 	 *
268 	 * Status: OPTIONAL
269 	 */
270 	void (* scan_start)(struct Scsi_Host *);
271 
272 	/*
273 	 * Fill in this function to allow the queue depth of this host
274 	 * to be changeable (on a per device basis).  Returns either
275 	 * the current queue depth setting (may be different from what
276 	 * was passed in) or an error.  An error should only be
277 	 * returned if the requested depth is legal but the driver was
278 	 * unable to set it.  If the requested depth is illegal, the
279 	 * driver should set and return the closest legal queue depth.
280 	 *
281 	 * Status: OPTIONAL
282 	 */
283 	int (* change_queue_depth)(struct scsi_device *, int);
284 
285 	/*
286 	 * This functions lets the driver expose the queue mapping
287 	 * to the block layer.
288 	 *
289 	 * Status: OPTIONAL
290 	 */
291 	void (* map_queues)(struct Scsi_Host *shost);
292 
293 	/*
294 	 * SCSI interface of blk_poll - poll for IO completions.
295 	 * Only applicable if SCSI LLD exposes multiple h/w queues.
296 	 *
297 	 * Return value: Number of completed entries found.
298 	 *
299 	 * Status: OPTIONAL
300 	 */
301 	int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num);
302 
303 	/*
304 	 * Check if scatterlists need to be padded for DMA draining.
305 	 *
306 	 * Status: OPTIONAL
307 	 */
308 	bool (* dma_need_drain)(struct request *rq);
309 
310 	/*
311 	 * This function determines the BIOS parameters for a given
312 	 * harddisk.  These tend to be numbers that are made up by
313 	 * the host adapter.  Parameters:
314 	 * size, device, list (heads, sectors, cylinders)
315 	 *
316 	 * Status: OPTIONAL
317 	 */
318 	int (* bios_param)(struct scsi_device *, struct block_device *,
319 			sector_t, int []);
320 
321 	/*
322 	 * This function is called when one or more partitions on the
323 	 * device reach beyond the end of the device.
324 	 *
325 	 * Status: OPTIONAL
326 	 */
327 	void (*unlock_native_capacity)(struct scsi_device *);
328 
329 	/*
330 	 * Can be used to export driver statistics and other infos to the
331 	 * world outside the kernel ie. userspace and it also provides an
332 	 * interface to feed the driver with information.
333 	 *
334 	 * Status: OBSOLETE
335 	 */
336 	int (*show_info)(struct seq_file *, struct Scsi_Host *);
337 	int (*write_info)(struct Scsi_Host *, char *, int);
338 
339 	/*
340 	 * This is an optional routine that allows the transport to become
341 	 * involved when a scsi io timer fires. The return value tells the
342 	 * timer routine how to finish the io timeout handling.
343 	 *
344 	 * Status: OPTIONAL
345 	 */
346 	enum scsi_timeout_action (*eh_timed_out)(struct scsi_cmnd *);
347 	/*
348 	 * Optional routine that allows the transport to decide if a cmd
349 	 * is retryable. Return true if the transport is in a state the
350 	 * cmd should be retried on.
351 	 */
352 	bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
353 
354 	/* This is an optional routine that allows transport to initiate
355 	 * LLD adapter or firmware reset using sysfs attribute.
356 	 *
357 	 * Return values: 0 on success, -ve value on failure.
358 	 *
359 	 * Status: OPTIONAL
360 	 */
361 
362 	int (*host_reset)(struct Scsi_Host *shost, int reset_type);
363 #define SCSI_ADAPTER_RESET	1
364 #define SCSI_FIRMWARE_RESET	2
365 
366 
367 	/*
368 	 * Name of proc directory
369 	 */
370 	const char *proc_name;
371 
372 	/*
373 	 * This determines if we will use a non-interrupt driven
374 	 * or an interrupt driven scheme.  It is set to the maximum number
375 	 * of simultaneous commands a single hw queue in HBA will accept.
376 	 */
377 	int can_queue;
378 
379 	/*
380 	 * In many instances, especially where disconnect / reconnect are
381 	 * supported, our host also has an ID on the SCSI bus.  If this is
382 	 * the case, then it must be reserved.  Please set this_id to -1 if
383 	 * your setup is in single initiator mode, and the host lacks an
384 	 * ID.
385 	 */
386 	int this_id;
387 
388 	/*
389 	 * This determines the degree to which the host adapter is capable
390 	 * of scatter-gather.
391 	 */
392 	unsigned short sg_tablesize;
393 	unsigned short sg_prot_tablesize;
394 
395 	/*
396 	 * Set this if the host adapter has limitations beside segment count.
397 	 */
398 	unsigned int max_sectors;
399 
400 	/*
401 	 * Maximum size in bytes of a single segment.
402 	 */
403 	unsigned int max_segment_size;
404 
405 	/*
406 	 * DMA scatter gather segment boundary limit. A segment crossing this
407 	 * boundary will be split in two.
408 	 */
409 	unsigned long dma_boundary;
410 
411 	unsigned long virt_boundary_mask;
412 
413 	/*
414 	 * This specifies "machine infinity" for host templates which don't
415 	 * limit the transfer size.  Note this limit represents an absolute
416 	 * maximum, and may be over the transfer limits allowed for
417 	 * individual devices (e.g. 256 for SCSI-1).
418 	 */
419 #define SCSI_DEFAULT_MAX_SECTORS	1024
420 
421 	/*
422 	 * True if this host adapter can make good use of linked commands.
423 	 * This will allow more than one command to be queued to a given
424 	 * unit on a given host.  Set this to the maximum number of command
425 	 * blocks to be provided for each device.  Set this to 1 for one
426 	 * command block per lun, 2 for two, etc.  Do not set this to 0.
427 	 * You should make sure that the host adapter will do the right thing
428 	 * before you try setting this above 1.
429 	 */
430 	short cmd_per_lun;
431 
432 	/* If use block layer to manage tags, this is tag allocation policy */
433 	int tag_alloc_policy;
434 
435 	/*
436 	 * Track QUEUE_FULL events and reduce queue depth on demand.
437 	 */
438 	unsigned track_queue_depth:1;
439 
440 	/*
441 	 * This specifies the mode that a LLD supports.
442 	 */
443 	unsigned supported_mode:2;
444 
445 	/*
446 	 * True for emulated SCSI host adapters (e.g. ATAPI).
447 	 */
448 	unsigned emulated:1;
449 
450 	/*
451 	 * True if the low-level driver performs its own reset-settle delays.
452 	 */
453 	unsigned skip_settle_delay:1;
454 
455 	/* True if the controller does not support WRITE SAME */
456 	unsigned no_write_same:1;
457 
458 	/* True if the host uses host-wide tagspace */
459 	unsigned host_tagset:1;
460 
461 	/* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */
462 	unsigned queuecommand_may_block:1;
463 
464 	/*
465 	 * Countdown for host blocking with no commands outstanding.
466 	 */
467 	unsigned int max_host_blocked;
468 
469 	/*
470 	 * Default value for the blocking.  If the queue is empty,
471 	 * host_blocked counts down in the request_fn until it restarts
472 	 * host operations as zero is reached.
473 	 *
474 	 * FIXME: This should probably be a value in the template
475 	 */
476 #define SCSI_DEFAULT_HOST_BLOCKED	7
477 
478 	/*
479 	 * Pointer to the SCSI host sysfs attribute groups, NULL terminated.
480 	 */
481 	const struct attribute_group **shost_groups;
482 
483 	/*
484 	 * Pointer to the SCSI device attribute groups for this host,
485 	 * NULL terminated.
486 	 */
487 	const struct attribute_group **sdev_groups;
488 
489 	/*
490 	 * Vendor Identifier associated with the host
491 	 *
492 	 * Note: When specifying vendor_id, be sure to read the
493 	 *   Vendor Type and ID formatting requirements specified in
494 	 *   scsi_netlink.h
495 	 */
496 	u64 vendor_id;
497 
498 	/* Delay for runtime autosuspend */
499 	int rpm_autosuspend_delay;
500 };
501 
502 /*
503  * Temporary #define for host lock push down. Can be removed when all
504  * drivers have been updated to take advantage of unlocked
505  * queuecommand.
506  *
507  */
508 #define DEF_SCSI_QCMD(func_name) \
509 	int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)	\
510 	{								\
511 		unsigned long irq_flags;				\
512 		int rc;							\
513 		spin_lock_irqsave(shost->host_lock, irq_flags);		\
514 		rc = func_name##_lck(cmd);				\
515 		spin_unlock_irqrestore(shost->host_lock, irq_flags);	\
516 		return rc;						\
517 	}
518 
519 
520 /*
521  * shost state: If you alter this, you also need to alter scsi_sysfs.c
522  * (for the ascii descriptions) and the state model enforcer:
523  * scsi_host_set_state()
524  */
525 enum scsi_host_state {
526 	SHOST_CREATED = 1,
527 	SHOST_RUNNING,
528 	SHOST_CANCEL,
529 	SHOST_DEL,
530 	SHOST_RECOVERY,
531 	SHOST_CANCEL_RECOVERY,
532 	SHOST_DEL_RECOVERY,
533 };
534 
535 struct Scsi_Host {
536 	/*
537 	 * __devices is protected by the host_lock, but you should
538 	 * usually use scsi_device_lookup / shost_for_each_device
539 	 * to access it and don't care about locking yourself.
540 	 * In the rare case of being in irq context you can use
541 	 * their __ prefixed variants with the lock held. NEVER
542 	 * access this list directly from a driver.
543 	 */
544 	struct list_head	__devices;
545 	struct list_head	__targets;
546 
547 	struct list_head	starved_list;
548 
549 	spinlock_t		default_lock;
550 	spinlock_t		*host_lock;
551 
552 	struct mutex		scan_mutex;/* serialize scanning activity */
553 
554 	struct list_head	eh_abort_list;
555 	struct list_head	eh_cmd_q;
556 	struct task_struct    * ehandler;  /* Error recovery thread. */
557 	struct completion     * eh_action; /* Wait for specific actions on the
558 					      host. */
559 	wait_queue_head_t       host_wait;
560 	const struct scsi_host_template *hostt;
561 	struct scsi_transport_template *transportt;
562 
563 	struct kref		tagset_refcnt;
564 	struct completion	tagset_freed;
565 	/* Area to keep a shared tag map */
566 	struct blk_mq_tag_set	tag_set;
567 
568 	atomic_t host_blocked;
569 
570 	unsigned int host_failed;	   /* commands that failed.
571 					      protected by host_lock */
572 	unsigned int host_eh_scheduled;    /* EH scheduled without command */
573 
574 	unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
575 
576 	/* next two fields are used to bound the time spent in error handling */
577 	int eh_deadline;
578 	unsigned long last_reset;
579 
580 
581 	/*
582 	 * These three parameters can be used to allow for wide scsi,
583 	 * and for host adapters that support multiple busses
584 	 * The last two should be set to 1 more than the actual max id
585 	 * or lun (e.g. 8 for SCSI parallel systems).
586 	 */
587 	unsigned int max_channel;
588 	unsigned int max_id;
589 	u64 max_lun;
590 
591 	/*
592 	 * This is a unique identifier that must be assigned so that we
593 	 * have some way of identifying each detected host adapter properly
594 	 * and uniquely.  For hosts that do not support more than one card
595 	 * in the system at one time, this does not need to be set.  It is
596 	 * initialized to 0 in scsi_register.
597 	 */
598 	unsigned int unique_id;
599 
600 	/*
601 	 * The maximum length of SCSI commands that this host can accept.
602 	 * Probably 12 for most host adapters, but could be 16 for others.
603 	 * or 260 if the driver supports variable length cdbs.
604 	 * For drivers that don't set this field, a value of 12 is
605 	 * assumed.
606 	 */
607 	unsigned short max_cmd_len;
608 
609 	int this_id;
610 	int can_queue;
611 	short cmd_per_lun;
612 	short unsigned int sg_tablesize;
613 	short unsigned int sg_prot_tablesize;
614 	unsigned int max_sectors;
615 	unsigned int opt_sectors;
616 	unsigned int max_segment_size;
617 	unsigned long dma_boundary;
618 	unsigned long virt_boundary_mask;
619 	/*
620 	 * In scsi-mq mode, the number of hardware queues supported by the LLD.
621 	 *
622 	 * Note: it is assumed that each hardware queue has a queue depth of
623 	 * can_queue. In other words, the total queue depth per host
624 	 * is nr_hw_queues * can_queue. However, for when host_tagset is set,
625 	 * the total queue depth is can_queue.
626 	 */
627 	unsigned nr_hw_queues;
628 	unsigned nr_maps;
629 	unsigned active_mode:2;
630 
631 	/*
632 	 * Host has requested that no further requests come through for the
633 	 * time being.
634 	 */
635 	unsigned host_self_blocked:1;
636 
637 	/*
638 	 * Host uses correct SCSI ordering not PC ordering. The bit is
639 	 * set for the minority of drivers whose authors actually read
640 	 * the spec ;).
641 	 */
642 	unsigned reverse_ordering:1;
643 
644 	/* Task mgmt function in progress */
645 	unsigned tmf_in_progress:1;
646 
647 	/* Asynchronous scan in progress */
648 	unsigned async_scan:1;
649 
650 	/* Don't resume host in EH */
651 	unsigned eh_noresume:1;
652 
653 	/* The controller does not support WRITE SAME */
654 	unsigned no_write_same:1;
655 
656 	/* True if the host uses host-wide tagspace */
657 	unsigned host_tagset:1;
658 
659 	/* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */
660 	unsigned queuecommand_may_block:1;
661 
662 	/* Host responded with short (<36 bytes) INQUIRY result */
663 	unsigned short_inquiry:1;
664 
665 	/* The transport requires the LUN bits NOT to be stored in CDB[1] */
666 	unsigned no_scsi2_lun_in_cdb:1;
667 
668 	/*
669 	 * Optional work queue to be utilized by the transport
670 	 */
671 	char work_q_name[20];
672 	struct workqueue_struct *work_q;
673 
674 	/*
675 	 * Task management function work queue
676 	 */
677 	struct workqueue_struct *tmf_work_q;
678 
679 	/*
680 	 * Value host_blocked counts down from
681 	 */
682 	unsigned int max_host_blocked;
683 
684 	/* Protection Information */
685 	unsigned int prot_capabilities;
686 	unsigned char prot_guard_type;
687 
688 	/* legacy crap */
689 	unsigned long base;
690 	unsigned long io_port;
691 	unsigned char n_io_port;
692 	unsigned char dma_channel;
693 	unsigned int  irq;
694 
695 
696 	enum scsi_host_state shost_state;
697 
698 	/* ldm bits */
699 	struct device		shost_gendev, shost_dev;
700 
701 	/*
702 	 * Points to the transport data (if any) which is allocated
703 	 * separately
704 	 */
705 	void *shost_data;
706 
707 	/*
708 	 * Points to the physical bus device we'd use to do DMA
709 	 * Needed just in case we have virtual hosts.
710 	 */
711 	struct device *dma_dev;
712 
713 	/*
714 	 * We should ensure that this is aligned, both for better performance
715 	 * and also because some compilers (m68k) don't automatically force
716 	 * alignment to a long boundary.
717 	 */
718 	unsigned long hostdata[]  /* Used for storage of host specific stuff */
719 		__attribute__ ((aligned (sizeof(unsigned long))));
720 };
721 
722 #define		class_to_shost(d)	\
723 	container_of(d, struct Scsi_Host, shost_dev)
724 
725 #define shost_printk(prefix, shost, fmt, a...)	\
726 	dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
727 
shost_priv(struct Scsi_Host * shost)728 static inline void *shost_priv(struct Scsi_Host *shost)
729 {
730 	return (void *)shost->hostdata;
731 }
732 
733 int scsi_is_host_device(const struct device *);
734 
dev_to_shost(struct device * dev)735 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
736 {
737 	while (!scsi_is_host_device(dev)) {
738 		if (!dev->parent)
739 			return NULL;
740 		dev = dev->parent;
741 	}
742 	return container_of(dev, struct Scsi_Host, shost_gendev);
743 }
744 
scsi_host_in_recovery(struct Scsi_Host * shost)745 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
746 {
747 	return shost->shost_state == SHOST_RECOVERY ||
748 		shost->shost_state == SHOST_CANCEL_RECOVERY ||
749 		shost->shost_state == SHOST_DEL_RECOVERY ||
750 		shost->tmf_in_progress;
751 }
752 
753 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
754 extern void scsi_flush_work(struct Scsi_Host *);
755 
756 extern struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *, int);
757 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
758 					       struct device *,
759 					       struct device *);
760 #if defined(CONFIG_SCSI_PROC_FS)
761 struct proc_dir_entry *
762 scsi_template_proc_dir(const struct scsi_host_template *sht);
763 #else
764 #define scsi_template_proc_dir(sht) NULL
765 #endif
766 extern void scsi_scan_host(struct Scsi_Host *);
767 extern int scsi_rescan_device(struct scsi_device *sdev);
768 extern void scsi_remove_host(struct Scsi_Host *);
769 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
770 extern int scsi_host_busy(struct Scsi_Host *shost);
771 extern void scsi_host_put(struct Scsi_Host *t);
772 extern struct Scsi_Host *scsi_host_lookup(unsigned int hostnum);
773 extern const char *scsi_host_state_name(enum scsi_host_state);
774 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
775 					    enum scsi_host_status status);
776 
scsi_add_host(struct Scsi_Host * host,struct device * dev)777 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
778 					     struct device *dev)
779 {
780 	return scsi_add_host_with_dma(host, dev, dev);
781 }
782 
scsi_get_device(struct Scsi_Host * shost)783 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
784 {
785         return shost->shost_gendev.parent;
786 }
787 
788 /**
789  * scsi_host_scan_allowed - Is scanning of this host allowed
790  * @shost:	Pointer to Scsi_Host.
791  **/
scsi_host_scan_allowed(struct Scsi_Host * shost)792 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
793 {
794 	return shost->shost_state == SHOST_RUNNING ||
795 	       shost->shost_state == SHOST_RECOVERY;
796 }
797 
798 extern void scsi_unblock_requests(struct Scsi_Host *);
799 extern void scsi_block_requests(struct Scsi_Host *);
800 extern int scsi_host_block(struct Scsi_Host *shost);
801 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
802 
803 void scsi_host_busy_iter(struct Scsi_Host *,
804 			 bool (*fn)(struct scsi_cmnd *, void *), void *priv);
805 
806 struct class_container;
807 
808 /*
809  * DIF defines the exchange of protection information between
810  * initiator and SBC block device.
811  *
812  * DIX defines the exchange of protection information between OS and
813  * initiator.
814  */
815 enum scsi_host_prot_capabilities {
816 	SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
817 	SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
818 	SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
819 
820 	SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
821 	SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
822 	SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
823 	SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
824 };
825 
826 /*
827  * SCSI hosts which support the Data Integrity Extensions must
828  * indicate their capabilities by setting the prot_capabilities using
829  * this call.
830  */
scsi_host_set_prot(struct Scsi_Host * shost,unsigned int mask)831 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
832 {
833 	shost->prot_capabilities = mask;
834 }
835 
scsi_host_get_prot(struct Scsi_Host * shost)836 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
837 {
838 	return shost->prot_capabilities;
839 }
840 
scsi_host_prot_dma(struct Scsi_Host * shost)841 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
842 {
843 	return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
844 }
845 
scsi_host_dif_capable(struct Scsi_Host * shost,unsigned int target_type)846 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
847 {
848 	static unsigned char cap[] = { 0,
849 				       SHOST_DIF_TYPE1_PROTECTION,
850 				       SHOST_DIF_TYPE2_PROTECTION,
851 				       SHOST_DIF_TYPE3_PROTECTION };
852 
853 	if (target_type >= ARRAY_SIZE(cap))
854 		return 0;
855 
856 	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
857 }
858 
scsi_host_dix_capable(struct Scsi_Host * shost,unsigned int target_type)859 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
860 {
861 #if defined(CONFIG_BLK_DEV_INTEGRITY)
862 	static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
863 				       SHOST_DIX_TYPE1_PROTECTION,
864 				       SHOST_DIX_TYPE2_PROTECTION,
865 				       SHOST_DIX_TYPE3_PROTECTION };
866 
867 	if (target_type >= ARRAY_SIZE(cap))
868 		return 0;
869 
870 	return shost->prot_capabilities & cap[target_type];
871 #endif
872 	return 0;
873 }
874 
875 /*
876  * All DIX-capable initiators must support the T10-mandated CRC
877  * checksum.  Controllers can optionally implement the IP checksum
878  * scheme which has much lower impact on system performance.  Note
879  * that the main rationale for the checksum is to match integrity
880  * metadata with data.  Detecting bit errors are a job for ECC memory
881  * and buses.
882  */
883 
884 enum scsi_host_guard_type {
885 	SHOST_DIX_GUARD_CRC = 1 << 0,
886 	SHOST_DIX_GUARD_IP  = 1 << 1,
887 };
888 
scsi_host_set_guard(struct Scsi_Host * shost,unsigned char type)889 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
890 {
891 	shost->prot_guard_type = type;
892 }
893 
scsi_host_get_guard(struct Scsi_Host * shost)894 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
895 {
896 	return shost->prot_guard_type;
897 }
898 
899 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
900 
901 #endif /* _SCSI_SCSI_HOST_H */
902